An antenna for receiving digital television signals transmitted by a wireless television station serves as an interface between a media device and an environment of signal transmission. The antenna is configured for conversion between an electrical signal and an electromagnetic signal, and is further configured to generate a suitable radiation pattern through its own antenna structure, so as to lower the attenuation rate at a specific frequency and to promote Signal-to-Noise ratio (SNR) of a received signal.
Referring to FIG. 1, a conventional antenna apparatus 710 for receiving digital television signals is shown. The conventional antenna apparatus 710 is disposed on dielectric substrate 720 having a symmetrical axis (L). The dielectric substrate 720 is substantially rectangular. The conventional antenna apparatus 710 has a pair of coupling radiating parts 711, which are symmetrical to each other with respect to the symmetrical axis (L). The two coupling radiating parts 711 define an empty space 712 which is substantially triangular. The slow wave effect may be achieved by virtue of equivalent capacitance and equivalent inductance resulting from the coupling radiating parts 711 of the conventional antenna apparatus 710, so that a balun circuit can be omitted. However, an area occupied by the coupling radiating parts 711 on the dielectric substrate 720 is excessively large and thus incurs higher manufacturing cost. The attenuation rate of the conventional antenna apparatus 710 is presented in a dotted line depicted in FIG. 5, and is required to be improved within a digital television frequency band ranging from 470 MHz to 700 MHz.